Call For Discussion: Dual Boot

[Seb]

hi there

this is a call to discuss ways to dual boot with pdaxrom as "main" rom

how could this possibly be achieved?

currently i'm thinking of what follows where at least the kernel would have to stay the same

it should be something like this:
- copy whole directory/ file structure to sd card
- invent new runlevel or just change existing one
- write script to be called at first in this new runlevel
- this script should do something like remount /proc and /dev and chroot to previously copied directory/ file structure similar to gentooforzaurus

what do you think? feasible? are there any better ways? possibly ways where kernel does not have to be the same?

regards
seb

[ThC]

the problem is not about booting scripts as we already have some (like the one I'm using taken from oz booting scripts wich could permit us to dual boot with minor mods)... the problem is about libc used in different distrib ...
It would require either compile a pdaXrom with same libc as oz or sharp rom (only way to have a realy useable dual boot with sharp rom) or recompile an oz rom using same libc as pdaXrom ...
I already asked for people able to recompile oe using pdaXrom's libc but noone answered ... btw I don't have time for now to discover oz build system as I have to finish my work on pdaXrom one before ...

[pgas]

dual booting should be possible now, using linux as a bootloader:

-Kernel switcher modules for c3000 altavista translation

- kexec seems to be working with latest 2.6.15 kernel (see for instance  this page)

[sashz]

dual booting should be possible now, using linux as a bootloader:

-Kernel switcher modules for c3000 altavista translation

- kexec seems to be working with latest 2.6.15 kernel (see for instance  this page)
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That easy with new mmc sd module - compile new mmcsd module inside kernel with cmdline="root=/dev/mmcda1 init=/sbin/init", unpack pdaXrom( or debian for example) rootfs to sd or mmc card, and with pyro's kernel reloader module boot up new system.

[jgardia]

the problem is not about booting scripts as we already have some (like the one I'm using taken from oz booting scripts wich could permit us to dual boot with minor mods)... the problem is about libc used in different distrib ...
It would require either compile a pdaXrom with same libc as oz or sharp rom (only way to have a realy useable dual boot with sharp rom) or recompile an oz rom using same libc as pdaXrom ...
I already asked for people able to recompile oe using pdaXrom's libc but noone answered ... btw I don't have time for now to discover oz build system as I have to finish my work on pdaXrom one before ...
[div align=\"right\"][a href=\"index.php?act=findpost&pid=115283\"][{POST_SNAPBACK}][/a][/div]

I think that we (pdaXrom) should move to a newer glbic version. We are using 2.2.5 and oe are using 2.3.[2-3], I think.
you are asking them to downgrade glibc's version, why don't we upgrade ours?

Regards,

Jose

Proud TOSA user

[ThC]

@jgardia : I guess this one is to be asked to sashz as he's the main developper of pdaXrom main branch ... i'm not even an "official" pdaXrom developper and I'm only working on the c3000 port on my free time (not as frequently as I would like to btw) ... beside, every package would have to be recompiled for a new release of pdaXrom that would use a newer libc (or we may be able to have some compat packages as we have for running some rc8 packages on rc10+).
Btw I don't know if sashz have time to work on this as it would probably require a lot of patches to be remade for everything to compile well .
I may try by myself to compile a pdaXrom version against glibc2.3.3 but I can't guarantee that I'll be able to achieve anything ...

I were proposing to compile an OZ distrib with downgraded glibc because OZ claims to be compatible with any glibc , which pdaXrom doesn't

EDIT : I'm not asking OZ team to downgrade their main branch to an older glibc, but am talking about haveing an other OZ-based distrib dedicated to multi-boot

EDIT2 : after 5 minutes of reflexion, i think kernel swapping is definitely the way to go as either we'll lose the advantage of one of the worlds as not being able to have their software library useable "out of the box"  (or move pdaXrom's main dev branch to a newer glibc which doesn't depend on me ^^)

[Seb]

hmm..
but why is glibc relevant when interfering in init-v-process? i mean, there is only kernel and sbin/init before that, isn't it?

[ThC]

well, I dont think there's a real need to interfere in init-v process to dual-boot, the kernel swithing can be implemented either before or during the sbin/init scripts loading ... the glibc concerns are about being able to use the same kernel for the 2 used distribs which would be easyer (I'm a little bit lazy sometimes )...

[Hrw]

OpenZaurus 3.5.4 use glibc 2.3.5+cvs20050627

After 3.5.4 we will work on getting 2.6 for c7x0 and cxx00 machines (maybe tosa too). Our current 2.6 kernel has kexec functionality so you can flash 2.6 kernel, boot it and then use kexec to load any other kernel. Ofcourse switching from that other kernel require reboot or kexec support.